C/C++实现跨文件共享全局变量详解

#pragma once
 
#include <iostream>
 
using namespace std;
 
struct para {
 
    bool  state;
    int   num;
    string name;
};
 
//声明全局变量
extern  para  g_static_para;

#pragma once
#include "Common.h"
 
//定义全局变量
para  g_static_para;

#pragma once
 
#include <iostream>
#include "Common.h"
 
using namespace std;
 
class init_class
{
 
public:
 
    void init();
 
};

#include "init_class.h"
#include "Common.h"
 
 
void init_class::init()
{
    cout << "参数初始化 全局变量 g_static_para" << endl;
    g_static_para.state = true;
    g_static_para.num = 20;
    g_static_para.name = "测试信息2";
}

#pragma once
 
#include <iostream>
#include "Common.h"
 
using namespace std;
 
class use_class
{
 
public:
 
    void print();
 
};

#include "use_class.h"
 
void use_class::print() {
 
    cout << "打印参数 全局变量 g_static_para" << endl;
    cout << "g_static_para.state:" << g_static_para.state << endl;
    cout << "g_static_para.num:" << g_static_para.num << endl;
    cout << "g_static_para.name:" << g_static_para.name << endl;
}

#pragma once
#include <iostream>
#include "Common.h"
#include "init_class.h"
#include "use_class.h"
 
using namespace std;
 
int main()
{
    std::cout << "Hello World!\n";
 
    init_class ic;
    use_class uc;
 
    std::cout << "----------------------\n";
    g_static_para.state = false;
    g_static_para.num = 10;
    g_static_para.name = "测试信息1";
    uc.print();
 
    std::cout << "----------------------\n";
    ic.init();
    std::cout << "----------------------\n";
    uc.print();
}